The effect of including various structural polysaccharides in pig diets on ileal and faecal digestibility of amino acids and minerals

Abstract

Ten pigs with average initial weight of 40 kg fitted with ileo-caecal re-entrant cannulae were used in order to determine the effect of inclusion of different structural polysaccharides in the diet on ileal and faecal digestibilities of amino acids and minerals. The experiment comprised 4 treatments: (I) 100% control diet; (II) 95% control diet+5% pectin; (III) 95% control diet+5% cellulose; (IV) 95% control diet+5% ground straw. The ileal digestibility of organic matter was reduced by cellulose inclusion. The same effect occurred for the faecal digestibility of organic matter after cellulose and straw-meal inclusion. The ileal digestibility of protein was reduced after inclusion of straw-meal in the diet. The following amino acids showed a reduced ileal digestibility after 5% straw-meal inclusion in the diet: isoleucine; lysine; phenylalanine; threonine; valine; alanine; aspartic acid; glutamic acid; tyrosine. The faecal digestibility of protein did not differ among diets. With the exception of the apparent faecal digestibility of calcium, none of the determined ileal and faecal mineral digestibilities were significantly lower, as an average, in pigs fed the diets in which the structural polysaccharides were included. When pectin was included, the ileal digestibilities of Na, K, Mg, Ca and P were slightly depressed, while over the whole digestive tract there was no effect. The amount of Na that passed the distal ileum was 4.6 to 5.2 times higher than the Na intake.